Radio loud-speaker



y 3, 1929. P. P. SCHROEDER ,7

RADIO LOUD SPEAKER Filed May 31, 1927 fnvenror 34 F u ara e 13/ Patented July 23, 1929.

'UNITED STATES PATENT OFFICE.

Application filed Iay 81, 1927. Serial No. 195,818.

My invention relates to improvements in radio loud speakers, and has a more particular reference to that type of loud speaker wherein a paper or parchment material is an ployed as the ultimate tone producing agent. Heretofore considerable criticism has been directed against the operation of these parchment dia hragm speakers. The most important o the imperfect ualities of this type of speaker is due to t e construction of same, whereby the extreme high and low 0scillations are drowned by attempted impressions on a single diaphragm of a given resonance.

In these conventional speakers, at single dia hragm is employed which must accommo ate both the extreme high and low oscillations. In other words, a single diaphragm is provided which must emit vibrations of varying high and low pitches. v

An object of my invention is to overcome this imperfect condition and the elimination of the almost frequent intolerable sound emissions from the distortion of the diaphragm caused by one amplitude of oscillations overcoming and drowning an accompanying group.

To produce this desired result, I have provided a loud speaker wherein I employ two or more diaphragms of varying sound producing qualities. These diaphragms are actu-- ated by the vibrations of a single electro-magnetically operated diaphragm unit, so that the amplitude of oscillations flowing the articulated circuit will become partial to the respective diaphragms of corresponding resonance.

- In the drawings Figure 1 is a perspective view of the pre ferred construction of my invention in its entirety.

2 is a vertical sectional view of the same, showing the means employed for vibratin the several diaphra ms.

In t e drawing wherein li e numerals des ignate like parts of my invention, a box-like structure 1 is provided with suitable supporting members .2 for supporting an electromagnetic diaphragm unit 3 of conventional construction. This unit is rovided with the usual electro magnetic 00' s and the usual dia hragm vibratedthrough the attraction of the magnetic coils.

The top of this box-like structure is closed by a suitable panel 4, or else the to may be actually left open if desired. Tlie front wall of this structure is formed of a twoply panel 5 having openings 6 formed therein and further formed with a pair of enlarged circular openings 7 in open registry to eachother. The low tone dia hragm 8 of larger diameter than the circu ar openings in the pair of front panels, is constructed of preferably a disk of substantially stiff archment and with the outer edge portion t ereof bein held between the circumferential edge portions of the annular opening.

remainin walls 9 of this box-like structure including the bottom wall 13, are preferabl of thin paper material and are considera 1y larger in area than the diaphragm 8 of the front wall. These thin paper walls are in themselves diaphragms, and are provided along with the low tone diaphragm of the front wall with buttons 10 located centrally on the inner sides thereof- Connected to these buttons, are connecting I wires 11 which radiate from a central wire 14 having its lower extremity connected to the button on the inner side of they bottom wall 13. These wires are of a semi-ri id metal and are preferably of steel. The wires 11 in arrangement are inclined from the button on the side walls to their point of connection to the central wire 1. Suitable feet or leg members 14 are provided for supportin the structure.

11 operation, while the coils of the unit 3 are electrically ener 'zed, the consequential vibration of the diap ragm thereof, is transmitted through the central wire 14,.and distributed over the radial wires 11, to their respective diaphragms.

Now it will be seen that some vibrations will be too weak or extremely too frequent for registration on the high resonance diaphragm, but as'the wires become sensitive to the more intent and prolonged vibrations, the low resonance diaphragm will then be set in motion. Thus, the low tone diaphragm will not be attracted by the high pitch tones, but will only be susceptible of low tone vibrations.

Having thus described my invention, what I claim as new is In a sound reproducing device including a vibratory unit, a plurality of diaphragms of varying resonance arranged in angular rela tion to each other, a strand of semi-ri id mastrand, said branch strands being of semiterial connected at one end to the vi ratory rigid material, each of which is connected to unit, a yieldable structure to which the oppothe axial strand in oblique respect to its dia- 10 site end of said flange is attached, said strands phragm. I

5 being disposed in substantially axial relation In testimony whereof I afiix my signature. to the diaphragm, and a branch strand connecting each of the diaphragms to the axial PAUL P. SCI-IROEDER. 

